James lennant mckee



I. T. 'McKEE.

'DRAFT APPARATUS FOR FURNACES,

APPLICATION FILED FEB. I8. ms.

1 ,3 1 8,782 Patented Oct. 14, 1919.

aim 'rn1\n. m1\rr GKEEQO BRUNSWICK, cAivaDA, nssienon or ONE-HALF TO JOHN, RUSSELL THORNIBEERY, or SEAFORD, ENGLAND. 1

e DRAFT APPARATUS FOR FURNACES.

Specification of Letterslate'nt. .Patntdflct. 14, 1919.

Application filed February 18, 1 91s. Seria1 No.;2 17,739.

To all whom it may concern Be it 'known that I J AMES TENNANT MoKnn,1a subject of the King of'England,

residing at New Brunswiclnin Canada, have invented certain new and useful Improves ments in Draft Appantus for Furnaces, of

which the following is a spec 'Thisfinventio'n relates to furnaces comprising a plurality. of fuel chambers each havinga grate intended to be fired in turn and its objectiis to provide that the fresh smoky products of combustion arising after the firing of one grate can be dealt with in a companion chamberupon whose grate the fuel is incandescent.

The'principal feature of the present invention is therefore the combination with a plurality'of fuel-chambers each having a grate and a wall between and separating the two adjoining chambers but having, in it an opening at or near the fire-door end of the wall, or blast-devices whereby the draft over anygrate normally .flowing directly therefrom toward the bridge, can be forced reversel alon that rate and caused to flow through the aforesaid openinginto the com panion chamber and along the grate in the latter toward the bridge.

In the accompanying drawings Figure 1 is a sectional diagrammatic plan View taken on the line 11 in Fig. 2 through a pair of fuel chambers according to the present invention,

Fig. 2 is a vertical section taken on the irregular line 22 of Fig. l and Fig. 3 is a sectional detailed View of a three-way valve.

In these drawings, A is a supply-pipe for air, preferably heated, derived from any convenient source and leading to' a valve V from which branches V V extend to what may be termed change-valves CV CV the former being allocated to the left-hand fuel chamber LH having the grate G and the latter to the right-hand fuel chamber having the grate G The two change-valves are controllable manually. If preferred, however, these valves may be operated automatically by any automatic control apparatus.

From the control-valve CV a branch 1 extends through the furnace-wall and into the bridge B through which it can discharge toward the fire-door, as indicated by the arrow at the outlet 0 in the bridge. Another branch 2 extends from the changethe bridge.

Between the fuel chambers LH' and RHis.

a division-wall XV, (which may be hollow, as shown) dlYlCllllg the'comb-ustion space above the grates into two parts but having in it an opening 0 at or near the fire-'doorend of the wall. v7

Although in, Fig. 2 of the drawings the grates are shown as .being at the under-side of a cylindrlcal b01ler L, it is to be under-' stood that this arrangement of furnaces is equally applicableto a boiler of any suitable type. v

As to the operation of the invention, let it be assumed that both the grates have been charged with fuel which is burning well and that the direction" of the draft from both chambersis normaland that which is indicatedby the arrows ND, and next assume that fresh fuel is put. on to the left-hand grate G. Immediately upon the closing of the fire-door of the left-hand chamber, the change-valve CV is moved into the position shown in Fig. 3 to shut off the supply of air to the branch 2 and to deliver a supply along the pipe 1 which, issuing from the bridge B at O reverses the draft over the left-hand grate G and propels the fresh products of combustion arising from the green fuel thereon, reversely along that grate, that is to say toward the fire-door and through the opening 0 in the wall W into the combustion s oace in the companion chamber RH, so t at they will flow along the latter away from the fire-door over the incandescent fuel on the right-hand grate G which will burn up the smoke which comes through the opening 0. The change-valve CV is afterward operated manually or automatically, as soon as suflicient combustion on the left-hand grate is occurring, in such a manner as to restore the normal direction of draft in the left-hand chamber to that which is indicated by the arrow ND extending therefrom. Next the right-hand grate is fired and after the closing of the righthand fire-door, the change-valve CV is operated to effect a reversal of flow in the right-hand chamber so that the fresh prodacts of combustion"therefrom pass through bridge.

Although branches 2 andQ are shown as being employed to enhance the normal draft, these branches can be dispensed with in cases in which there is a good natural draft, leaving only the branches 1 and l to bring about either the manual or automatic reversal above described.

lVhat I claim as my invention and desire to secure by Letters Patent is 1. In a furnace, the combination with a plurality of fuel chambers each having a grate and a free outlet at'the bridge wall thereof, and a partition wall between and separating two adjacent chambers but having in it an opening near the front or firedoor end of the wall, of-forced-draft de vices one opening into the rear or bridge end of each fuel chamber and directed along the grate therein for causing the draft over the grate normally flowing directly toward the bridge wall to be reversed -alongth-at grate and forced'to flow-through the said opening into the adjacent fuel chamber and over the grate therein toward the bridge wall thereof, and means for controlling the forced draft devices, substantially as de scribed.

2. In a furnace, the combination with a plurality of fuel chambers each having a grate and a free outlet at the bridge wall thereof, and a partition wall between and separating each two adjacent. chambersbut having in it an opening nearthe frontor fire-door end of the wall, of a Systempf forced-draft pipes comprising two @valve-,

controlled branch pipes opening into each fuel chamber, one of said branch pipes in each chamber opening into the frontend thereof, and the other opening into the rear or bridge end thereof adj acentv to the outlet.

in thebridge wall and being directed along the grate therein for causing, the draft over the grate normally flowing directly toward the bridge end to be reversed along that grate and forced to flow throughthe said opening into an adjacent fuel chamber and over the grate therein toward the bridge end thereof, substantially as described.

In testimony whereof I affix my signature.

JAMES TEQTNANT McKEE.

Copies of this patent may be obtained -for five cents each, by addressing the Commissioner of Patents,

Washington, D. G. e 

